a) Field of the Invention
The present invention relates to a bearing system used in motors for capstan drives of VTRs, tape recorders and the like.
b) Background Art
Conventionally, a bearing system such as shown in FIG. 3 is used in a motor for capstan drives of VTRs and tape recorders (cf. Jap. Utility Model Application Laid-open No. Sho 64-50646).
In FIG. 3, the reference number 1 denotes a shaft which acts as a capstan shaft of a VTR or a tape recorder. The shaft 1 is rotatably supported via metal bearings 4, 4 by a substantially cylindrical bearing holder 3 which rests on the base plate 12 via a collar 3a. A boss 5 is fixed on the base 1a of the shaft 1. The end of the base 1a which protrudes from the boss 5 abuts against a thrust bearing element 6, which prevents the shaft 1 from moving further downward in the figure.
The thrust bearing element 6 is attached to a substantially cylindrical and blind angle member 7 which fixed underneath the base plate 12. In FIG. 3, the reference number 8 denotes a rotor yoke which is fixed on the outer periphery of the boss 5, 9 a rotor magnet fixed on the inner periphery of the rotor yoke 8, 10 a stator core fixed on the bearing holder 3, 11 a wiring provided on each of the salient poles (not shown) on the stator core 10, and 13 a belt which is wound about an annular V-groove 5a formed on the outer periphery of the boss 5 which causes a reel table, etc. (not shown) to rotate.
A bearing system having the construction described above is defective in that, due to fluctuation in the molding precision of the bearing holder 3, it is difficult to axially align the shaft 1 which is held rotatable via the metal bearings 4, 4 with the bearing holding 3.